AST Final (Hw 1-7)
Which of the following blackbody curves indicates the coldest object? - Frequency: 6.2 x 10^14 Hz & Wavelength: 480nm - Frequency: 6.2x 10^15 Hz & Wavelength: 48nm - Frequency: 6.2 x 10^13 Hz & Wavelength: 4.8 μm
- Frequency: 6.2 x 10^13 Hz & Wavelength: 4.8 μm
Warm temperatures in the summertime are chiefly due to which of the following reasons? - The days are longer during the summer months. - The sunlight hits the ground more directly during the summer months. - The Earth is significantly closer to the Sun during the summer months.
- The days are longer during the summer months - The sunlight hits the ground more directly during the summer months
Which of the following statements are true? - Gamma is named for its discoverer, Frederic Gamma. - Visible is named this because we can see these waves. - Infrared is named for the part of the spectrum with frequencies less than those of red light. - Ultraviolet is named for the part of the spectrum with frequencies greater than those of violet light. - Radio is named because of the way we hear these waves. - X-ray is named this because it is the least understood part of the spectrum.
- Visible is named this because we can see these waves. - Infrared is named for the part of the spectrum with frequencies less than those of red light. - Ultraviolet is named for the part of the spectrum with frequencies greater than those of violet light.
A circular orbit would have an eccentricity of
0
How much stronger is the gravitational pull of the Sun on Earth, at 1 AU, than it would be if Earth were at 10 AU, in the orbit of Saturn?
100 times stronger
You note that a particular star is directly overhead. It will be directly overhead again in
23 hours 56 minutes
The major axis for a new comet has been determined to be 100 AU. The eccentricity of the orbit was measured to be 0.94. What is the distance of closest approach to the Sun for this comet?
3 AU
Suppose an electron in some atom absorbs energy and transitions from level 1 up to level 4. Which of the following is a true statement regarding the electron transitions back down to level 1? - 4 to 2, followed by 2 to 1, is possible. Downward transitions can be any number of levels. - It can go from 4 to 1 only. The downward transition must match the upward one. - It must transition from 4 to 3, then 3 to 2, then 2 to 1. All downward transitions are one step at a time.
4 to 2, followed by 2 to 1, is possible. Downward transitions can be any number of levels.
The greatest distance above or below the ecliptic the Moon can move is
5.2 degrees
From the horizon to the observer's zenith is an angle of
90 degrees for everyone on the Earth
Which of the following is NOT one of Kirchhoff's laws? - A low-density, cool gas in isolation creates a continuous spectrum. - A low-density, cool gas absorbs photons from a continuous source, creating an absorption spectrum. - A low-density, hot gas emits an emission spectrum. - A luminous solid, liquid, or dense gas emits a continuous spectrum.
A low-density, cool gas in isolation creates a continuous spectrum.
Each of the four diagrams below represents the orbit of the same asteroid, but each one shows it in a different position along its orbit of the Sun. Imagine that you observed the asteroid as it traveled for one week, starting from each of the positions shown. Rank the positions based on the area that would be swept out by a line drawn between the Sun and the asteroid during the one-week period.
All are the same
Each of the four diagrams below represents the orbit of the same comet, but each one shows the comet passing through a different segment of its orbit around the Sun. During each segment, a line drawn from the Sun to the comet sweeps out a triangular-shaped, shaded area. Assume that all the shaded regions have exactly the same area. Rank the segments of the comet's orbit from left to right based on the length of time it takes the comet to move from Point 1 to Point 2.
All are the same
Which of the following regions of the elctromagnetic spectrum is useful for studying distant galaxies?
All of the above
What kind of spectrum does the Sun have?
An absorption spectrum
What is the primary advantage of techniques of radio interferometry?
An increase in resolving power
Who proposed the geocentric view that was accepted and used for more than 18 centuries?
Aristotle
What is the cause of the phases of the Moon?
As the Moon orbits the Earth, different parts of the side facing the Earth are illuminated by the Sun
Suppose you see the constellation Orion directly overhead around midnight in February. During which of the following months would it be directly overhead in the daytime (around noon)?
August
The universe is filled with objects of extreme temperatures and densities, both high and low. The differences among the three types of spectra result from the various physical conditions in which the light is emitted, or through which it travels, before it is observed on Earth. The following three diagrams illustrate the use of a simple spectroscope in a laboratory. Match each diagram to the appropriate spectra. Note that a light bulb can be thought of as a hot, dense source of radiation.
Continuous: - Hot bulb Emission: - Heated hydrogen gas Absorption: - Hot bulb and Cool gas
There are three general types of spectra: continuous, emission, and absorption. Each is characterized by a different distribution of the wavelengths (i.e., colors) of radiation. Sort the images of the three types of spectra into the appropriate bins
Continuous: - Complete rainbow Emission: - Black strip with colored lines (2) Absorption: - Rainbow strip with black lines (2)
Which of these is not a form of electromagnetic radiation? - ultraviolet causing a suntan - light from your camp fire - DC current from your car battery - X-rays in the doctor's office radio - signals
DC current from your car battery
In the summer we observe different constellations than in the winter. This is because ________.
Earth has moved to the other side of its orbit
The Spitzer Space Telescope (SST) is stationed far from Earth because
Earth is a heat source and the telescope must be kept very cool.
A sidereal day is shorter than a solar day because ________.
Earth is moving around the Sun
Arrange the following objects in order of increasing size.
Earth, Solar System, Galaxy, Universe
No astronomical object that produces a continuous visible spectrum of light has ever been observed. However, there are many astronomical objects that produce emission or absorption spectra. Read the following descriptions of astronomical objects, and then sort the labeled images into the appropriate bins according to the type of spectrum each object produces. - Emission nebula: a cloud of hot, interstellar gas glowing as a result of one or more nearby young stars that ionize the gas. - Planetary nebula: a glowing cloud of hot, low-density gas that is ejected from a red-giant star. - Sun: a glowing ball of extremely dense gas powered by nuclear fusion in its core, but surrounded by a low-density, cooler atmosphere. - Atmosphere on Titan: a layer of cool, low-density gas confined close to the surface of Titan, one of Saturn's moons.
Emission spectra: - Emission nebula: a cloud of hot, interstellar gas glowing as a result of one or more nearby young stars that ionize the gas. - Planetary nebula: a glowing cloud of hot, low-density gas that is ejected from a red-giant star. Absorption spectra: - Emission nebula: a cloud of hot, interstellar gas glowing as a result of one or more nearby young stars that ionize the gas. - Planetary nebula: a glowing cloud of hot, low-density gas that is ejected from a red-giant star.
In non-ionized hydrogen, for instance, what does a higher orbital state have more of than a lower orbital state?
Energy
Each of the following items states a temperature, but does not tell you whether the temperature is measured on the Fahrenheit, Celsius, or Kelvin scale. Match the items to the appropriate temperature scale.
Fahrenheit: - Ice cream is stored in freezers at 26. - A hot summer day might be 100. Celsius: - Water freezes into ice at 0. - Liquid water boils at 100. - A typical room temperature is 24. Kelvin: - The coldest possibletemperature is 0. - Water boils into gas phase at 373.15.
A telescope with an 8-inch mirror will collect twice as much light as one with a 4-inch mirror.
False
All the planets revolve around the Sun in the same direction, except for Venus and Uranus. True or False
False
Most lunar craters are volcanic in origin. True or False
False
The Moon keeps one side facing the Earth because it doesn't rotate on its axis. True or False
False
The Oort Cloud lies closer to the Sun than the Kuiper Belt. True or False
False
Consider again the diagrams from Parts D and E, which are repeated here. Again, imagine that you observed the asteroid as it traveled for one week, starting from each of the positions shown. This time, rank the positions (A-D) from left to right based on how fast the asteroid is moving at each position.
Fastest to Slowest: Asteroid is at the perihelion, Asteroid is on the right of the Sun near the perihelion, Asteroid is on the left of the Sun near the aphelion, Asteroid is at the aphelion
Consider again the diagrams from Parts A and B, which are repeated here. Again, assume that all the shaded areas have exactly the same area. This time, rank the segments of the comet's orbit based on the speed with which the comet moves when traveling from Point 1 to Point 2.
Fastest to Slowest: Point 1 is underneath Point 2 at the perihelion, Point 2 is left of Point 1 near the perihelion, Point 1 is left of Point 2 near the aphelion, Point 1 is above Point 2 at the aphelion
If Taurus is now rising at sunset, which constellation will rise at sunset next month?
Gemini
What are constellations?
Groups of stars making an apparent pattern in the celestial sphere
In the classical view of the atom, Bohr pictured electrons orbiting the positively charged nucleus similar to how the planets orbit the Sun. While this picture was not entirely correct, it provides a good framework in which to make calculations about the energies of electrons. Different from the predictions of Newtonian mechanics, which allows any energy to be possible, Bohr described the electron orbits (now called orbitals) as having specific energies. Rank the following electron energy states according to their electron energies.
HIghest energy to lowest energy: third excited state second excited state first excited state ground state
What was the greatest contribution of Tycho Brahe to astronomy?
He amassed a large number of precise measurements of stellar and planetary positions in the sky
The force of gravity between two objects obeys which of the following relationships?
It is attractive and increases if their masses increase
In general, what is true of the alpha star in a constellation?
It is the brightest star in the constellation
Which of the following is NOT true about the astronomical feature known as the "ecliptic"? - It forms a circle on the celestial sphere that is inclined at an angle of 23.5 degrees to the celestial equator. - It is the apparent path through the sky taken by the Sun over the course of the year. - It is the path taken by the Moon as it orbits Earth. - It passes through the constellations of the zodiac. - It is the plane in which Earth orbits the Sun.
It is the path taken by the Moon as it orbits Earth
Which of the following is NOT true of the celestial equator? - It is the projection of the Earth's equator onto the celestial sphere. - It traces the path of the Sun among the constellations. - It is equally distant from the north and south celestial poles. - It divides the sky into northern and southern hemispheres.
It traces the path of the Sun among the constellations
What is true of a blackbody?
Its energy peaks at the wavelength determined by its temperature.
What is the name of the temperature scale that places zero at the point where all atomic and molecular motion ceases?
Kelvin
_____'s theories were based on the very accurate observations made by _____.
Kepler, Tycho Brahe
The __________ extends from about beyond the orbit of Neptune to about twice the distance of Neptune from the Sun.
Kuiper belt
The Bohr model accounted for most of the general characteristics of the atom. However, the modern model based on quantum mechanics explains that, although the energy of each orbital is fixed, the orbital radius is actually an average distance. The result is a "cloud" where the electron would most probably be located. When electrons are excited to different energy levels, the average radii from the nucleus also changes. Rank the following electron energy states according to the average distance of the electron from the nucleus.
Largest distance to Smallest distance: third excited state second excited state first excited state ground state
Which of the following is NOT a reason to use a reflecting telescope rather than a refractor?
Lenses are harder to focus than mirrors.
If we double the diameter of a telescope's mirror, what happens to its light-gathering ability?
Light-gathering ability quadruples.
Consider again the diagrams from Part D, which are repeated here. Again, imagine that you observed the asteroid as it traveled for one week, starting from each of the positions shown. This time, rank the positions from left to right based on the distance the asteroid will travel during a one-week period when passing through each location.
Longest to Shortest: Asteroid is at the perihelion, Asteroid is on the right of the Sun near the perihelion, Asteroid is on the left of the Sun near the aphelion, Asteroid is at the aphelion
Consider again the diagrams from Part A, which are repeated here. Again, assume that all the shaded areas have exactly the same area. This time, rank the segments of the comet's orbit from left to right based on the distance the comet travels when moving from Point 1 to Point 2.
Longest to Shortest: Point 1 is underneath Point 2 at the perihelion, Point 2 is left of Point 1 near the perihelion, Point 1 is left of Point 2 near the aphelion, Point 1 is above Point 2 at the aphelion
A fatal flaw with Ptolemy's model is its inability to predict the observed phases of
Mercury and Venus
Which of the following is true about observations at wavelengths other than optical or radio?
Most observations at wavelengths other than optical or radio need to be conducted by space-based telescopes.
Consider the following objects. The wavelength emitted by the object is highlighted in red on the spectrum bar below the image. Decide which objects emit radiation that can penetrate Earth's atmosphere and reach the surface, and drag the objects into the appropriate bins.
Object's radiation can reach Earth's surface - Visible light (Yellow) - Visible light (Red-orange) Object's radiation cannot reach Earth's surface: - X-ray image (Purple, black background) - Gamma ray image (Purple, oval)
About a trillion comets are thought to be located far, far beyond Pluto in the
Oort cloud
How did Copernicus' model explain the retrograde motions of the planets?
Planets orbit the Sun at different speeds. When an inner, faster-moving planet "passes" a slower outer one, the slower planet appears to move backwards
Which of the following is a true statement (for people in the Northern Hemisphere)? - Polaris does not rise nor set - During the night, all the stars rise in the East and set in the West - All stars are fixed in the sky and do not appear to rise and set at all
Polaris does not rise nor set
Which of the following statements does NOT apply to the structure of atoms? - An electron cloud surrounds the nucleus. - One or more protons are always found in the nucleus. - Electrons can exist in excited states. - Protons and electrons make up the nucleus. - Neutrons are found in the nucleus.
Protons and electrons make up the nucleus.
The model of _____ used circular deferements and epicycles in a geocentric universe to explain planetary motions.
Ptolemy
What is meant in astronomy by the phrase "adaptive optics"?
Rapid modifications are made to the tilt and location of the elements of a telescope to correct for the effects of atmospheric and instrumental distortion.
Chromatic aberration in lenses is a result of which wave property of light?
Refraction
What is the name given to the phenomenon in which the apparent motion of the superior planets sometimes reverses?
Retrograde motion
The atom consists of three types of subatomic particles: protons, neutrons, and electrons. The electron is by far the lightest of the three, while the much heavier proton and neutron have masses very similar to each other. Two of the types of particles carry an electrical charge, while the third is neutral. Label the subatomic particles and appropriate charges by their relative locations.
Small blue particle on outside: electron, negative Red particle in nucleus: proton, positive Black particle in nucleus: neutron, neutral
Suppose a particular spectral line has a wavelength of 500 nm in the lab. If you look at the spectrum of star A, you see this line at 480 nm. Star B exhibits this line at 510 nm, and the line is measured to be at 530 nm in star C. Which of the following statements is true? - Star A is the only star moving away from us, star B and star C are both moving towards us (with star C moving towards us the fastest) - Star C is moving away from us faster than star B, star A is moving towards us. - Star A is moving the fastest of the three stars.
Star C is moving away from us faster than star B, star A is moving towards us.
In the geocentric Greek model, which of the following objects did not require an epicycle?
Sun
What will happen to the phases of the Moon as viewed from the Southern hemisphere?
The Moon will have the same phases, but will grow (wax) from the left side rather than the right
Why aren't there lunar and solar eclipses every month?
The Moon's orbit is inclined to the ecliptic
According to Newton, planets orbit in ellipses with what at the two foci?
The center of mass and nothing
Which of the following statements about the use of infrared telescopes is true?
The detector and telescope must be cooled to very low temperatures.
If the distance between the centers of two objects doubles, what happens to the gravitational pull between them if the masses do not change?
The force will decrease to one-fourth its previous size
How does the parallax of a nearby object compare to that of an object farther away?
The nearby object exhibits a larger parallax than the farther object
Which of the following is NOT one of Newton's Laws of Motion? - The orbital paths of the planets are elliptical (not necessarily circular), with the Sun at one focus. - The acceleration of an object is directly proportional to the net applied force and inversely proportional to the object's mass. - To every action there is an equal and opposite reaction. - An object at rest remains at rest, and a moving object continues to move forever in a straight line with constant speed, unless some external force changes their state of motion.
The orbital paths of the planets are elliptical (not necessarily circular), with the Sun at one focus
What property of a telescope influences its resolving power?
The size of the main mirror or lens
What physical property of Earth gives rise to the seasons?
The tilt of its rotation axis to the plane of its orbit
Which of the following is an advantage the Hubble Space Telescope has over ground-based telescopes?
There is no blurring due to the atmosphere.
What is true of radio telescopes?
They have poorer angular resolution than a refractor of the same size.
What will happen to the absorption and/or emission spectral lines of an object moving away from Earth at high speed?
They will be shifted toward the red end of the spectrum.
The observed spectral lines of a star are all shifted towards the red end of the spectrum. Which statement is true? - This is an example of the photoelectric effect. - The second law of Kirchhoff explains this. - This is an example of the Doppler effect. - The star is not rotating. - The star has a radial velocity towards us
This is an example of the Doppler effect.
All the terrestrial planets lie inside the asteroid belt. True or False
True
An emission line results from an electron falling from a higher to lower energy orbital around its atomic nucleus.
True
Asteroids, meteoroids, and comets are remnants of the early solar system. True or False
True
Compared to Earth, the Moon lacks a hydrosphere, atmosphere, and a magnetosphere.
True
One of the primary advantages of CCDs over photographic plates is the former's high efficiency in detecting light.
True
One source of the energy for volcanism and plate tectonics is radioactivity in the Earth's interior. True or False
True
Optical telescopes are usually used only at night, but radio telescopes can be used day or night.
True
Radio telescopes have poorer angular resolution than optical telescopes because radio waves have a much longer wavelength than optical waves.
True
Spectroscopy of a star can reveal its temperature, composition, and line-of-sight motion.
True
The Cassegrain reflector needs a primary concave main mirror and a smaller, convex secondary mirror to reflect light back through a hole in the primary.
True
The energy of a photon is inversely proportional to the wavelength of the radiation.
True
The tidal pull of the Moon is an example of a differential force, as the near and far sides of the Earth do not experience the same gravitational pull of the Moon.
True
When an electron in a hydrogen atom drops from the second to the first excited energy state it emits a bright red emission line called hydrogen alpha.
True
Which of the following is the best summary of Galileo's observations of the phases of Venus that directly refuted the Ptolemaic (geocentric) model? - According to the geocentric model, the disk of Venus should be largest when it shows a full phase. - According to the geocentric model, Venus should not exhibit any phases at all. - Venus can be seen to exhibit a full phase, which is predicted not to happen in the geocentric model.
Venus can be seen to exhibit a full phase, which is predicted not to happen in the geocentric model
Which of the following colors has a wavelength shorter than the others?
Violet
What fraction of the entire electromagnetic spectrum is spanned by visible light?
Visible light covers a tiny fraction of the electromagnetic spectrum.
For a wave of constant velocity, such as an electromagnetic wave, how are the wavelength and frequency related?
Wavelength is inversely proportional to the frequency.
The star Wolf 1061 has a parallax of 2.34 arc seconds, while the star Ross 652 has a parallax of 1.70 arc seconds. What can you correctly conclude?
Wolf 1061 is closer to Earth than Ross 652
Galileo found the rotation period of the Sun was approximately
a month
If you are in the Moon's umbral shadow, then you are witnessing
a total solar eclipse
Which of these age ranges best describes the lunar maria? a) 3.9 - 3.2 billion years b) 2.5 - 1.0 billion years c) a few million years to present lava flows seen erupting d) 100 - 65 million years e) 8.6 - 6.0 billion years
a) 3.9 - 3.2 billion years
What is the asteroid belt? a) A large group of asteroids with orbits located between Mars and Jupiter. b) A "ring" of asteroids around the Earth. c) A group of asteroids whose orbits take them within 1 AU of the Sun. d) Two groups of asteroids that share an orbit with Jupiter, orbiting 60 degrees ahead and behind the giant planet.
a) A large group of asteroids with orbits located between Mars and Jupiter.
Which of these theories seems to best explain the Moon's origin? a) Impact Theory b) Fusion Theory c) Conformation Theory d) Capture Theory e) Fission Theory
a) Impact Theory
When is Mercury visible in the night sky? a) It is seen at most for 2 hours, just before sunrise and just after sunset b) It can never be seen in the night sky c) It can be seen at any time of night d) It can be seen until about midnight
a) It is seen at most for 2 hours, just before sunrise and just after sunset.
Which of the following is NOT true about the relationship between Mercury's orbit and spin? a) One side of Mercury always faces the Sun b) The relationship is due to tidal forces from the Sun modifying Mercury's spin c) It is partially due to Mercury's highly elliptical orbit d) Mercury spins three times for every two times it orbits the Sun
a) One side of Mercury always faces the Sun
Which statement about asteroids is not true? a) Their images become blurry due to outgassing as the Sun heats them up b) Earthgrazers can cross not only our orbit, but even those of Venus and Mercury c) Most stay between the orbits of Mars and Jupiter d) They vary considerably in composition, reflectivity, and size e) Some have satellites of their own
a) Their images become blurry due to outgassing as the Sun heats them up
Which of the following statements about Earth's magnetic poles is true? a) They result from the spinning, electrically conducting liquid metal core deep within Earth b) They are caused by circulation of the solar wind around Earth c) They are fixed in space with respect to the Sun's direction at vernal equinox d) They vary from day to day due to changes in the ionosphere e) They are located at the same places as Earth's geographic poles
a) They result from the spinning, electrically conducting liquid metal core deep within Earth
Using the standard model of planetary system formation, scientists invoke catastrophic events to explain why... a) Uranus has an extremely tilted rotation axis b) Mercury has no moon c) there is no planet between Mars and Jupiter d) Pluto is not a gas giant.
a) Uranus has an extremely tilted rotation axis
The planet _____ has the least variation in temperatures on the surface between day and night. a) Venus b) Mars c) Mercury d) Earth
a) Venus
Why is dust important to the condensation sequence? a) Without dust, there would be nothing for the solar nebula gas to condense onto b) Without dust, water vapor in Earth's atmosphere would never have fallen to the surface as liquid water c) The dust contained carbon and other elements that are vital to the building of terrestrial planets d) The dust blocks the outer solar system from excess radiation from the Sun, allowing planetesimals to grow bigger out there
a) Without dust, there would be nothing for the solar nebula gas to condense onto
The Oort Cloud is believed to be... a) a spherical cloud of cometary nuclei far beyond the Kuiper Belt b) the circular disk of gas around the Sun's equator from which the planets formed c) a grouping of asteroids and meteoroids between the orbits of Mars and Jupiter d) a flattened belt of cometary nuclei just beyond the orbit of Neptune e) the great nebula found just below the belt stars of Orion
a) a spherical cloud of cometary nuclei far beyond the Kuiper Belt
Because of their low surface gravities, the Moon and Mercury lack _____. a) atmosphere b) water c) rotation d) hydrogen
a) atmosphere
At what phase would you expect to find extremely high and low tides? a) both new and full moons b) Moon phases do not impact the tides c) new moon d) first and third quarter e) full moon
a) both new and full moons
The greenhouse effect always results in a(n) _____ surface temperature. a) higher or hotter b) lower or colder c) lower or higher d) hotter or colder
a) higher or hotter
Venus' rotation on its axis... a) is clockwise, unlike most other solar system objects b) is highly tilted to its orbital plane, causing large seasonal changes c) shows it is tidally locked in its orbit around the Sun d) prevents us from seeing all of its surface features e) is the fastest of the terrestrial planets
a) is clockwise, unlike most other solar system objects
Planetary transits of exoplanets are rare because... a) most extrasolar systems are not seen edge-on b) the Earth's atmosphere interferes with our observations of transits c) most exoplanets are smaller than Pluto d) most stars are too bright for us to detect a planetary transit e) our telescopes are not powerful enough to detect them
a) most extrasolar systems are not seen edge-on
The age of the solar system is determined with _____ dating. a) radioactive b) Solar Nebula c) carbon d) Kepler
a) radioactive
The presence of a magnetic field is a good indication that... a) the Earth has a liquid metal outer core, spinning rapidly as it rotates b) the Earth's interior must be completely molten to the center c) the Earth's interior is similar to Mercury's, as both have fields d) a huge iron meteorite lies somewhere high up in the mantle, not in the core e) the Earth's interior has had time to solidify, with a rigid bar magnet created
a) the Earth has a liquid metal outer core, spinning rapidly as it rotates
Our most detailed maps of Venus come from... a) the Magellan space probe b) Earth-based radio telescopes. manned landings c) direct observation from Earth-based optical telescopes d) the Hubble Space Telescope
a) the Magellan space probe
Iron meteorites are believed to come from... a) the core of a differentiated asteroid, now broken up b) interstellar space c) the crust of a differentiated asteroid, now broken up d) a broken up cometary nucleus e) debris from the Kuiper Belt.
a) the core of a differentiated asteroid, now broken up
In Figure 6.3 in the textbook (Planetary Radar), part (b), the highest-frequency reflected radiation is received from... a) the upper part of the planet b) the center of the planet c) the lower part of the planet
a) the upper part of the planet
The difference in the Moon's gravitational force on the near and far sides of the Earth produces a(n) _____. a) tidal bulge b) high tide c) low tide d) tidal lock
a) tidal bulge
Astronomers analyze starlight to determine a star's - temperature. - composition. - motion. - all of the above.
all of the above
The ____________ is the maximum height or depth of the wave above or below the undisturbed state.
amplitude
According to Kepler's second law, Jupiter will be traveling most slowly around the Sun when at __________.
aphelion
The constellations are ________.
arbitrary regions that cover the entire sky, which astronomers have named
The Sun's tidal pull has slowed Mercury's rotation down to a period _____ that of its year. a) 3/4 b) 2/3 c) 1/3 d) 5/8
b) 2/3
How do we know what the surface of Venus looks like? a) By measuring the amount of thermal radiation being emitted b) By bouncing radio waves off its surface c) By landing a probe that took measurements for weeks d) By direct observation
b) By bouncing radio waves off its surface
What is the primary cause of the aurorae (Northern and Southern lights)? a) Reflections from polar ice b) Charged particles interacting with the atmosphere c) Cold air trapped over poles d) Drift of pollutants to the poles e) Diffraction in the atmosphere
b) Charged particles interacting with the atmosphere
What is the source of the material of a meteor shower? a) Collisions among asteroids b) Comets c) Oort cloud d) Solar wind
b) Comets
Which of the following objects are composed of material mostly unchanged since the formation of the solar system? a) Moons of jovian planets b) Comets and asteroids c) Moons of terrestrial planets d) Surfaces of terrestrial planets
b) Comets and asteroids
At which phase(s) of the Moon do the highest and lowest tides occur? a) First-quarter b) Full and new c) Third-quarter d) New and first-quarter
b) Full and new
What is the process of accretion? a) The process by which the solar nebula became heated during its collapse b) Growth of an object by the accumulation of matter c) The period of time during which the Sun swept away all of the excess material of the solar nebula d) The breakup of large objects by violent collisions with other bodies of similar size e) None of these is true
b) Growth of an object by the accumulation of matter
Which of the following is NOT a property of a terrestrial planet? a) High density b) High mass c) Rocky terrain d) Closeness to the Sun
b) High mass
What is the current leading theory for the Moon's formation? a) Capture of a wandering object by the gravitational field of Earth b) Impact of a large object with the early Earth, followed by coalescence and capture of the resulting fragments c) Fission of the early Earth into two fragments due to its rapid rotation d) Formation of both Earth and the Moon out of the same protoplanetary material as nearby objects e) None of the theories listed here gives an acceptable model.
b) Impact of a large object with the early Earth, followed by coalescence and capture of the resulting fragments
What is true of Mars? a) Definite microfossils have been found b) Iron oxide on the surface is responsible for its reddish color c) Its magnetic field is stronger than Earth's d) Its atmosphere is mostly water vapor e) A pool of water was discovered by the Mars Rover
b) Iron oxide on the surface is responsible for its reddish color
The _____ is a vast, spherical array of long period comet nuclei far beyond the orbit of Neptune. a) Andromeda b) Oort Cloud c) Kuiper Belt d) Nebula
b) Oort Cloud
The Manicouagan reservoir near Quebec is an example of... a) a volcanic event b) a large meteorite impact c) cometary debris d) Earth's interaction with a comet's dust tail e) a micrometeorite impact
b) a large meteorite impact
The tail of a comet always points... a) away from the Sun and disappears at perihelion b) away from the Sun and becomes longest and brightest at perihelion c) toward Earth and never varies d) in the direction of the comet's motion e) toward the Sun and disappears at perihelion.
b) away from the Sun and becomes longest and brightest at perihelion
The main constituent of the Martian atmosphere is... a) helium b) carbon dioxide c) hydrogen d) nitrogen e) methane
b) carbon dioxide
Venus's surface is permanently obscured by clouds. As a result, the surface has been studied primarily by... a) spectroscopy b) orbiting satellites using radar c) radar signals from Earth d) robotic landers
b) orbiting satellites using radar
Earth's magnetic field... a) is weakening the Van Allen radiation belts b) prevents charged particles in the solar wind from reaching the surface c) is a remnant of the solar nebula's magnetic field d) is the force behind plate tectonics e) lines intersect the atmosphere at the equator
b) prevents charged particles in the solar wind from reaching the surface
We determine the structure of the Earth's core using... a) satellite imaging b) seismic wave data c) deep mine shafts d) magnetic resonance imaging e) radar and sonar
b) seismic wave data
In composition, the _____ planets have rocky materials like the asteroids. a) gas b) terrestial c) dwarf d) ice
b) terrestial
Seismic waves are most useful for mapping... a) the density of the hydrosphere b) the Earth's core and mantle c) the surface of Venus with Magellan d) the surface of Mars with Global Surveyor e) the depths of the oceans.
b) the Earth's core and mantle
The scarps on Mercury were probably caused by... a) volcanism b) the crust cooling and shrinking c) tectonic activity d) meteorite bombardment e) a tidal bulge
b) the crust cooling and shrinking
At what phase are the tides least noticeable? a) waxing crescent b) third quarter c) full moon d) new moon e) waning gibbous
b) third quarter
The wide variation in the lunar surface temperature is due to its lack of which of the following? a) Geological activity b) A hydrosphere c) An atmosphere d) A magnetosphere
c) An atmosphere
Mars and Earth are similar in many ways and different in others. Which of the following is NOT one of the ways in which they are similar? a) Both have similar rotation rates b) Both have daily and seasonal cycles c) Both have similar densities d) Both have similar orbital inclinations
c) Both have similar densities
What material is rare in the atmosphere of Earth, but common in the atmospheres of Mars and Venus? a) Nitrogen b) Water vapor c) Carbon dioxide d) Molecular oxygen
c) Carbon dioxide
Earth and Venus likely started with very similar atmospheres. What happened to make them so different? a) A meteor struck Earth and stripped away most of its atmosphere b) A comet struck Venus, bringing a huge amount of carbon dioxide to its atmosphere c) Carbon dioxide dissolved into Earth's oceans and rocks, thinning out the atmosphere d) The incredible heat on Venus burned up most of the oxygen in its atmosphere e) All of the above are possible explanations that worked together to change the atmospheres of Venus and Earth
c) Carbon dioxide dissolved into Earth's oceans and rocks, thinning out the atmosphere
What caused the scarps found on Mercury? a) Impact craters b) Crust movements or tectonics c) Cooling of the planet and shrinking of the crust d) Lava flows
c) Cooling of the planet and shrinking of the crust
Which atmospheric gases are responsible for maintaining a livable temperature on Earth? a) Ozone and O2 b) O2 and N2 c) H2O and CO2 d) N2 and Ar
c) H2O and CO2
How does Mercury's rotation relate to the Sun? a) Its day is the same length as its year b) It does not spin at all, being tidal stopped by the solar tides c) Its rotation rate is 2/3 as long as its year, due to tidal resonances d) Its year is much shorter, only 88 days, than its slow rotation of 243 days on its axis e) It always keeps one face tidally locked toward the Sun, as our Moon does with us
c) Its rotation rate is 2/3 as long as its year, due to tidal resonances
Why were Martian volcanoes able to grow so large? a) Greater amounts of lava available b) Mars's hotter interior c) Mars's weaker surface gravity d) The lack of a significant Martian atmosphere e) The earlier formation of Mars compared to other planets
c) Mars's weaker surface gravity
Which of the following is NOT a property of our solar system we must account for in a theory of its origin? a) The orbits of the planets are nearly circular b) Most planets rotate on their axis in roughly the same sense as the Sun c) The Earth is the only planet that is known to have life d) The orbits of the planets all lie in nearly the same plane e) Our planetary system is highly differentiated
c) The Earth is the only planet that is known to have life
Which of the following is NOT a way in which the terrestrial and jovian planets differ? a) The terrestrial worlds are small and dense, whereas the jovian worlds are large and gaseous. b) The terrestrial planets that do have atmospheres have ones made of heavier compounds in general than the atmospheres of the jovian planets. c) The jovian planets have orbits that are highly inclined to the ecliptic and do not revolve in the same direction as the terrestrial planets. d) The terrestrial worlds have few or no moons, whereas the jovian worlds have many moons. e) The orbits of the terrestrial worlds are relatively close together, whereas the orbits of the jovian worlds are far apart.
c) The jovian planets have orbits that are highly inclined to the ecliptic and do not revolve in the same direction as the terrestrial planets.
What is true of the Moon's orbital and rotational periods? a) The orbital period is greatest at full moon. b) The orbital period is longer. c) They are equal. d) The rotational period is longer. e) The rotational period varies with the Moon's phase.
c) They are equal.
The region in which charged particles are trapped by our magnetic fields is the... a) ionosphere b) exosphere c) Van Allen radiation belt d) Aurora e) ozone layers
c) Van Allen radiation belt
Planetary orbits... a) are spaced more closely together as they get further from the Sun. b) have the Sun at their exact center. c) are almost circular, with low eccentricities. d) are evenly spaced throughout the solar system. e) are highly inclined to the ecliptic.
c) are almost circular, with low eccentricities
What is the main constituent of the atmosphere of Venus? a) hydrogen b) oxygen c) carbon dioxide d) nitrogen e) sulfuric acid
c) carbon dioxide
If a comet's ion tail is pointing perpendicular to its direction of travel, the comet is a) A comet's tail never points perpendicular to its motion b) close to or at aphelion c) close to or at perihelion d) moving closer to the Sun e) moving away from the Sun
c) close to or at perihelion
In the leading theory of solar system formation, the planets... a) are much older than the Sun b) were ejected from the Sun following a close encounter with another star c) formed from the same flattened, swirling gas cloud that formed the Sun d) are much younger than the Sun
c) formed from the same flattened, swirling gas cloud that formed the Sun
Exoplanets known as super-Earths... a) have masses comparable to that of Neptune b) have masses comparable to that of Jupiter c) have masses 2-10 times that of Earth d) have yet to be observed e) orbit extremely massive stars
c) have masses 2-10 times that of Earth
Sunlight absorbed by Earth's surface is reemitted in the form of... a) microwave b) ultraviolet radiation c) infrared d) visible
c) infrared
So far, beyond the solar system the extrasolar planets found have been mostly a) terrestrials with very elongated, distant orbits like comets b) large jovians orbiting solar-type stars about where our jovians are found c) large jovians very close to their star d) terrestrials very close to their star, and transiting its disk e) brown dwarfs much more massive than Jupiter.
c) large jovians very close to their star
What percentage of the surface of Venus could be characterized as continental-sized highlands? a) 100% b) 75% c) less than 10% d) about 30%, like the Earth e) 45%
c) less than 10%
As the solar nebula contracts, it... a) flattens out into the ecliptic plane around the Sun's poles b) loses angular momentum c) spins faster due to conservation of angular momentum d) cools due to condensation e) reverses its direction of rotation
c) spins faster due to conservation of angular momentum
Which of these is not a result of plate tectonics? a) the San Andreas Fault b) the Mid-Atlantic Rift c) the Grand Canyon d) the Andes e) the Philippine Trench
c) the Grand Canyon
The average rate of erosion on the Moon is far less than on Earth because... a) the Moon's magnetic field protects it from the solar wind better than ours does b) the Moon's mare long ago dried up, so there is no more wave erosion there c) the Moon lacks wind, water, and an atmosphere d) the crust of the Moon is much denser than the Earth's crust e) the Moon is much younger than the Earth
c) the Moon lacks wind, water, and an atmosphere
Water on Earth was... a) created by chemical reactions involving hydrogen and oxygen shortly after Earth formed b) produced by volcanoes in the form of steam c) transported here by comets d) accreted from the solar nebula
c) transported here by comets
Almost all of our atmospheric gases lie in the... a) mesosphere b) ionosphere c) troposphere d) stratosphere e) ozone layer
c) troposphere
In what part of our atmosphere do we live? a) mesosphere b) ionosphere c) troposphere d) stratosphere e) exosphere
c) troposphere
Figure 1.17 in the textbook (Gravity), showing the motion of a ball near Earth's surface, depicts how gravity [IMAGE DESCRIPTION: A ball thrown up from the surface of a massive object, such as a planet, is pulled continuously down (arrows) by the gravity of that planet—and, conversely, the gravity of the ball continuously pulls the planet (although very, very little).]
causes the ball to accelerate downward
Imagine you are holding a small ball below you so that you look down on its "North Pole." Turn the ball in a counterclockwise direction. Continue to turn it in that direction as you slowly raise it above your head so that you are looking up at its "South Pole." In what direction is it rotating now?
clockwise
The primary purpose of a telescope is to
collect a large amount of light and bring it into focus.
The bright spherical part of a comet observed when it is close to the Sun is the
coma
A dense, hot body will give off a(n) _____ spectrum.
continuous
Meteoric material dates the formation of the solar system at about_____ billion years. a) 2.0 b) 2.5 c) 1.5 d) 4.6 e) 10
d) 4.6
How does Valles Marineris differ from the Grand Canyon? a) It is larger b) It is steeper c) It was not made by water d) All of the above are true
d) All of the above are true
Why is Mars's atmosphere so much thinner than Earth's? a) Mars has a much lower gravity than Earth b) A large meteor struck Mars and caused much of its atmosphere to fly off into space c) A large amount of carbon dioxide dissolved into the ancient oceans of Mars, and was then "locked" up in carbonate rocks d) All of the above may have contributed
d) All of the above may have contributed
The largest asteroid, and probably the only one to be a spherical "world" is... a) Vesta b) Ida c) Gaspra d) Ceres e) Eros
d) Ceres
What phenomenon causes all weather and wind on Earth? a) Earth's magnetic field b) Tides c) Plate tectonics d) Convection
d) Convection
What natural phenomenon on Earth provides information on the structure of Earth's core? a) Plate tectonics b) Aurorae c) Oceanic ridges d) Earthquakes e) Volcanoes
d) Earthquakes
Which of the following methods have astronomers used to detect extrasolar planets? a) Directly observing the extrasolar planet around its parent star b) Observing the transit of an extrasolar planet across its star by measuring the decrease in light received from the star c) Measuring the Doppler shift of the light from a star to see how the star "wobbles" due to the gravity of the planet d) Extrasolar planets have been detected using all of the above methods.
d) Extrasolar planets have been detected using all of the above methods.
What was the cause of the Caloris Basin? a) A shield volcano b) Extensive lava flows c) Subduction of a large piece of the crust d) Impact of a large asteroid
d) Impact of a large asteroid
Which planet shows the widest range of surface temperatures between day and night? a) Earth b) Venus c) Uranus d) Mercury e) Mars
d) Mercury
How does the age of the lunar highlands compare to the age of the lunar maria? a) The maria are billions of years older b) The maria are billions of years younger c) They are the same age d) The maria are a few hundred million years younger e) The maria a few hundred million years older
d) The maria are a few hundred million years younger
Why do asteroids look like "dots" to Earth-based telescopes? a) They are very far away, in the outermost solar system. b) They move very fast in their orbits. c) Gravity has formed all of them into perfect spheres. d) They are very small.
d) They are very small.
Which of these gets so bright as to be seen in daylight at times? a) Mars b) Jupiter c) Saturn d) Venus e) Mercury
d) Venus
Would you expect Mars to experience seasons as Earth does? Why? a) No, because it is too far from the Sun b) No, because its orbit is not synchronized c) Yes, because it has the same orbital characteristics as Earth d) Yes, because its rotation axis is tilted relative to its orbital axis
d) Yes, because its rotation axis is tilted relative to its orbital axis
The nucleus of a comet is typically... a) a few hundred kilometers across, and bright, shiny white from its ices b) located between the orbits of Mars and Jupiter c) very durable, made of iron d) a few kilometers in size, and very low in density e) a few meters in diameter
d) a few kilometers in size, and very low in density
The process by which small debris condenses into planetesimals is _____. a) induction b) collision c) coma d) accretion
d) accretion
The first figure in Discovery 5-2 shows that CO2 levels in Earth's atmosphere began to rise rapidly... a) in 1600 b) in the middle ages c) in the late 20th century d) in the mid-19th century
d) in the mid-19th century
A solid body from the outer solar system that arrives intact on the Earth's surface is called a(n) _____. a) asteroid b) meteor c) comet d) meteorite
d) meteorite
The solar system is differentiated because... a) the light elements in the inner solar system were carried off as comets b) the heavy elements in the outer solar system sank to the center c) the light elements in the inner solar system fell into the Sun d) only rocky and metallic particles could form close to the Sun
d) only rocky and metallic particles could form close to the Sun
The Trojan asteroids are found... a) closer on average to the Sun than is the Earth b) with the others, between Mars and Jupiter; their red color gives them their name c) beyond Neptune, with orbits similar to Pluto's d) sixty degrees ahead or behind Jupiter, sharing its orbit about the Sun e) orbiting around the Kuiper Belt body Hector
d) sixty degrees ahead or behind Jupiter, sharing its orbit about the Sun
The atmospheric gases primarily responsible for our greenhouse effect are... a) oxygen and carbon dioxide b) hydrogen and helium c) argon and water vapor d) water vapor and carbon dioxide e) carbon monoxide and methane
d) water vapor and carbon dioxide
The effect of a cool, dilute gas between an observer and a continuous hot source is that ________.
dark absorption lines will appear in the spectrum
Meteor showers are... a) usually annual events, as the orbits again intersect b) caused by the Earth passing near the orbit of an Earthgrazing asteroid c) caused by the Earth passing near the orbit of an old short-period comet d) Both A and B are correct e) Both A and C are correct.
e) Both A and C are correct.
Which of the following characterizes a shield volcano? a) It can erupt only briefly before being dragged off the hot spot b) It cannot grow very large, for it has a very short span of eruption c) It is formed by moving tectonic plates d) It cannot get as high as Mt. Everest before the thin crust starts slumping e) It sits above a hot spot in the planet's mantle
e) It sits above a hot spot in the planet's mantle
Which of the following are the jovian planets? a) only Jupiter b) Jupiter, Saturn, Uranus, Neptune, and Pluto c) only Jupiter and Saturn d) everything past Mars and the asteroid belt e) Jupiter, Saturn, Uranus, and Neptune only
e) Jupiter, Saturn, Uranus, and Neptune only
Which three worlds have almost identical densities? a) Mercury, Mars, and our Moon b) Earth, Moon, and Mars c) Mercury, Earth, and Mars d) Deimos, Phobos, and our Moon e) Mercury, Venus, and Earth
e) Mercury, Venus, and Earth
What is true about solar system densities? a) The asteroids all have about the same density. b) Saturn has the same density as water. c) Planetary density increases with increasing distance from the Sun. d) In differentiated bodies, the denser materials lie near their surfaces. e) The denser planets lie closer to the Sun.
e) The denser planets lie closer to the Sun.
Which of the following is not icy in composition? a) most jovian satellites b) Kuiper Belt Objects c) the polar cap of Mars d) comet nuclei e) asteroids
e) asteroids
Which of the following have an icy composition? a) most asteroids b) the surface of Mars c) meteorites and most asteroids d) meteoroids e) comets
e) comets
The ingredients of a typical comet's nucleus are most likely ________. a) iron particles covered by liquid water, methane, and liquid hydrogen b) carbon monoxide, liquid nitrogen, silicon gas, and sodium metal c) metallic hydrogen with methane and ammonia ices and rocks d) sulfur, ammonia, alcohol, and liquid carbon dioxide e) dust and rocky particles trapped in methane, ammonia, and water ice
e) dust and rocky particles trapped in methane, ammonia, and water ice
Which of the following layers of the Earth is unique among the terrestrial planets? a) mantle b) crust c) core d) ionosphere e) hydrosphere
e) hydrosphere
When strong solar winds are displaced poleward by our magnetic fields, we get... a) droughts and dust bowls in the American West b) sunspots c) hurricanes in the tropics d) the Van Allen radiation belts e) intense auroral displays.
e) intense auroral displays.
Density is defined as... a) size divided by weight b) weight per square inch c) mass times weight d) weight divided by the planet's radius e) mass per unit volume.
e) mass per unit volume.
The critical part of the atmosphere for protecting life on the ground from excessive ultraviolet radiation is the... a) stratosphere b) hydrosphere c) ionosphere d) troposphere e) ozone layer
e) ozone layer
According to the Solar Nebula theory, planets... a) should be randomly oriented to their star's equator b) will revolve opposite the star's rotation c) should orbit perpendicular to their star's equator d) should be extremely rare e) should be a common result of star formation
e) should be a common result of star formation
The most detailed look we've had of an asteroid comes from... a) ground based optical images b) high-altitude UV spectroscopy c) ground based radar images d) Earth orbital X-ray images e) spacecraft sent to an asteroid
e) spacecraft sent to an asteroid
In noting that the Earth is "differentiated," we mean that... a) the Earth is very different than any other planet we study b) the Earth's magnetic field varies at different locations on the globe c) the density of oceanic basalt is less than that of granite on the mountain tops d) the radioactive heating in the core is increasing with time e) the density increases as you descend downward toward the core
e) the density increases as you descend downward toward the core
The rate of cratering in the lunar highlands shows us that... a) they must be younger than the older, darker mare b) the largest impacts are the youngest, such as Copernicus and Tycho c) most of the asteroids must have hit the Moon, not the Earth d) the oldest rocks are at least as old as the mare, but some craters are much younger e) they range from 4.6 - 4.4 billion years old, on average
e) they range from 4.6 - 4.4 billion years old, on average
The extent to which Mars' orbit differs from a perfect circle is called its __________.
eccentricity
The number of ____________ identifies whether an atom carries a charge as an ion or is neutral.
electrons
Earth orbits in the shape of a/an __________ around the Sun.
ellipse
Kepler's first law worked, where Copernicus' original heliocentric model failed, because Kepler described the orbits as
elliptical, not circular
Retrograde motion was explained by the Greeks by inventing which of the following?
epicycles
Earth is located at one __________ of the Moon's orbit.
focus
The number of waves that pass a point each second measures ________.
frequency
When the Moon is directly opposite the Sun in the sky, its phase is
full
According to Newton's laws, the planets orbit the Sun due to _____.
gravity
The design of modern X-ray telescopes depends on
grazing incidence optics
In astronomy, an interferometer can be used to
improve the angular resolution of radio telescopes.
Table 3.1 in the textbook (Astronomy at Many Wavelengths) suggests that the best frequency range in which to study the hot (million-kelvin) gas found among the galaxies in the Virgo cluster would be
in X rays
The best way to study young stars hidden behind interstellar dust clouds would be to use
infrared light.
When used in a single instrument to greatly enhance its resolution, the four separate mirrors of the VLT act as a(n) _____.
interferometer
Wien's law states that the wavelength of the peak radiation emitted by a blackbody is ________ the temperature of a blackbody.
inversely proportional to
If you are in the Earth's umbra on the Earth's surface, then
it is night time
Copernicus proposed a heliocentric model for the solar system primarily because ________.
it was much simpler than the Ptolemaic model
What is the resolution of a telescope?
its ability to distinguish two adjacent objects close together in the sky
Why would astronomers measure the parallax angle of a planet or star? What physical property of that object are they trying to determine?
its distance
How does orbital speed at aphelion compare to the speed at perihelion?
lower
Particles ejected from a comet can cause a(n) __________ on Earth
meteor shower
In general, the spectral lines of molecules are
more complex than those of atoms.
If Earth's orbit around the Sun were to double in size, the new "year" would be
more than 2 current Earth years
A solar eclipse can only happen during a
new moon
A comet's __________ is the frozen portion of a comet.
nucleus
Medium A blocks more of a certain wavelength of radiation than medium B. Medium A has a higher
opacity.
As shown in Figure 1.8 (Venus Phases), Galileo's observations demonstrated that Venus must be [IMAGE DESCRIPTION: Both the Ptolemaic and the Copernican models of the solar system predict that Venus should show phases as it moves in its orbit. (a) In the Copernican picture, when Venus is directly between Earth and the Sun, its unlit side faces us and the planet is invisible to us. As Venus moves in its orbit, progressively more of its illuminated face is visible from Earth. Note the connection between the orbital phase and the apparent size of the planet: Venus seems much larger in its crescent phase than when it is full because it is much closer to us during its crescent phase. This is the behavior actually observed. The insets at bottom left and right are photographs of Venus taken at two of its crescent phases (Courtesy of New Mexico State University). (b) In the Ptolemaic model, the full phase of the planet cannot be explained. Seen from Earth, Venus reaches only a "fat crescent," yet never a full phase, then begins to wane as it nears the Sun. (Note that both these views are from a sideways perspective; from overhead, both orbits are very nearly circular.)]
orbiting the Sun
According to Kepler's second law, Pluto will be traveling fastest around the Sun when at __________.
perihelion
When a planet's orbit takes it closest to the Sun, it's called
perihelion
In electromagnetic waves, the electric and magnetic fields vibrate _____ to each other.
perpendicular
A comet's __________ stretches directly away from the Sun.
plasma tail
That Polaris will not always be the pole star is due to
precession shifting the celestial pole
The Arecibo radio telescope is laid out like which optical telescope design?
prime focus reflector
The number of __________ identifies the type of element.
protons
A star much cooler than the Sun would appear
red
As telescopes become larger and larger, astronomers favor ________.
reflecting telescopes, in part because large lenses and mirrors sag under their own weight, and it is easier to support a mirror along its entire back side than it is to support a lens only around its edge
It is diffraction that limits the ________ of a telescope of a given objective diameter.
resolution
The mathematical form of Kepler's third law measures the period in years and the __________ in astronomical units (AU)
semimajor axis
Which of these was NOT seen telescopically by Galileo? - Venus' phase cycle - Four moons around Jupiter - craters and mare on the Moon - stellar parallax - sunspots
stellar parallax
When does the Full Moon rise?
sunset
The "guest star" observed by the Chinese in 1054 is now known to have been a(n) _____.
supernova
In an annular eclipse,
the Sun appears as a thin, bright ring
In the Northern Hemisphere, it is colder in the winter than in the summer because ________.
the Sun shines down at more of an angle during the winter
A jar filled with gas is placed directly in front of a second jar filled with gas. Using a spectroscope to look at one jar through the other you observe dark spectral lines. The jar closest to you contains
the cooler gas.
The fact that the Earth has moved along its orbit in the time it took to rotate once is the reason for
the difference between solar and sidereal time
This diagram explains [IMAGE DESCRIPTION: The figure shows three diagrams, labeled from "a" to "c". Diagram "a" shows the Sun on the left and Earth on the right. They are connected with a horizontal line. Earth's position is labeled initially. There is point A at the left edge of Earth. An arrow points from this point to the left, in the direction of the Sun. Diagram "b" shows a similar situation, but now Earth is located a bit higher, above the initial horizontal line. This position is labeled After 1 sidereal day. The arrow from point A keeps pointing horizontally to the left. There is an additional arrow encircling Earth; its direction is counterclockwise. Diagram "c" is similar to diagram b, but the label for Earth's position is After 1 solar day now. The arrow from point A is now directed to the Sun. The angle between the horizontal line and the line connecting the Sun and Earth is 0.986 degrees.]
the difference between solar time and sidereal time
The major axis for a particular planet is known. In order to determine the perihelion and the aphelion, what other information about the planet is needed?
the eccentricity of the orbit
The total energy radiated by a blackbody depends on
the fourth power of its temperature.
The most important advantage of CCDs over film is that
they record much more light in a given exposure time.
A calculation of how long it takes a planet to orbit the Sun would be most closely related to Kepler's
third law of planetary motion.
If the Moon appears half lit, and is almost overhead about 6:00 AM, its phase is
third quarter
The blackbody curve of a star moving toward Earth would have its peak shifted
toward higher energies.
The time interval of 365.242 days is defined as the
tropical year
What problem does adaptive optics correct?
turbulence in the Earth's atmosphere that creates twinkling
The two forms of electromagnetic (E-M) radiation that experience the least atmospheric opacity are
visible light and radio waves.
The ___________ is the number of waves that pass a point per unit of time, usually waves per second.
wave frequency
The _________ is a measurement of the amount of time needed for a wave to repeat itself at some point in space.
wave period
The ____________ is the number of waves that pass a point per unit of time, usually waves per second.
wavelength
You are in the Southern Hemisphere. One night you see the Moon appear as quarter moon. What do you expect the Moon to look like about four days later?
waxing gibbous
The interval from new Moon to first quarter is about a(n)
week
The radiation our eyes are most sensitive to is the color
yellow-green at about 550 nm.
In the Kelvin scale, absolute zero lies at
zero K.
